Comparison of lateral entry with crossed entry pinning for pediatric supracondylar humeral fractures: a meta-analysis

BACKGROUND: The standard treatment for severe displaced pediatric supracondylar humeral fracture (SCHF) is closed reduction and percutaneous pin fixation. However, controversy persists concerning the optimal pin fixation technique. The purpose of this study was to compare the safety and efficacy on the configuration of lateral entry only with crossed entry pin fixation for SCHF, including Gartland type II and type III fractures in children. METHODS: Published literatures, including retrospective studies, prospective studies, and randomized controlled trials, presenting the probability of poor functional consequence of elbow and/or loss of reduction and/or iatrogenic ulnar nerve injury and/or superficial infection and/or cubitus varus were included. Statistical analysis was performed with the Review Manager 5.3 software. RESULTS: Twenty-four studies were included in the present meta-analysis involving 1163 patients with lateral entry pins and 1059 patients with crossed entry pins. An excellent score of Flynn criteria occurred more commonly in patients who treated with crossed pins than in patients with lateral pins only (RR = 0.93; 95% CI 0.87–0.99; P = 0.03). In accordance with previous systematic review, the incidence of iatrogenic ulnar nerve injury in crossed entry group was significantly more than in lateral entry group with statistical difference (RR = 0.26; 95% CI 0.14–0.47; P < 0.0001). And, results of subgroup analysis on iatrogenic ulnar nerve injury based on experimental design of retrospective study (RR = 0.23; 95% CI 0.10–0.52; P < 0.0004) and randomized control trial (RR = 0.29; 95% CI 0.10–0.79; P < 0.02) were similar. CONCLUSIONS: In consideration of the contradictoriness of lateral entry with two pins only (possible risk of poor functional consequence of elbow) and crossed entry pins (risk of iatrogenic ulnar nerve injury), the recommended strategy for the treatment of SCHF is the lateral entry technique with introducing divergent three pins which can provide a stable configuration and avoid the injury of the ulnar nerve. And additional protective measures for the ulnar nerve should be taken by surgeons that wish for the more stable structure with the crossed entry technique.