Risk factors related reduction loss in nonoperatively treated Type II supracondylar humerus fractures

BACKGROUND: Controversies continue about the optimal treatment method for extension Type II supracondylar humerus fractures (SCHFs). Although most patients are successfully treated with closed reduction and plaster casting, in some patients, the reduction initially obtained is lost during the time in the plaster cast. The aim of this study was to determine the risk factors causing reduction loss. METHODS: A retrospective examination was made of the data of 103 patients with Type II extension SCHF treated with closed reduction and plaster cast fixation between 2012 and 2018. Reduction loss was evaluated in respect of patient variables, fracture characteristics as obliquity and metaphyseal fragmentation, fixation method, and plaster cast parameters. RESULTS: The 103 patients evaluated comprised 62 males and 41 females with a mean age of 5.4±2.5 years (2–11.6 years). Successful treatment was achieved with closed reduction and plaster cast fixation in 81 (79%) patients and reduction loss was observed in 22 (21%) patients. The reduction loss of fractures showing high oblique in the sagittal plane was 3.17-fold higher than low sagittal oblique fractures (95% CI: 0.99–10.03, p<0.05). The risk of reduction loss in fractures with metaphyseal fragmentation was found to be 6.5-fold higher (95% CI: 1.6–26.5, p<0.01). No statistically significant relationship was determined between reduction loss and Gartland subtype, age, gender, the presence of rotation initially, plaster cast angle, and the soft-tissue/inner cast width ratio. CONCLUSION: According to our study group, 79% of extension Type II fractures can be successfully treated with closed reduction and plaster casting. Sagittal plane obliquity and metaphyseal fragmentation are risk factors for reduction loss independent of Gartland subtype.