Outcomes of conservatively treated midshaft clavicle fractures with butterfly fragment

The aim of this study was to evaluate whether fracture shortening, displacement, and the length of butterfly fragments were reliable radiographic indicators of secondary healing failure in displaced midshaft clavicle fractures with butterfly fragments and to determine whether these radiographic parameters were effective in predicting healing disorders and could be utilized as prognostic factors.

Between January 2015 and January 2020, a total of 31 adult patients (29 males, 2 females; mean age: 43.6±13.2 years; range, 21 to 74 years) who presented with a closed displaced clavicle shaft fracture with butterfly fragments and were treated conservative using figure of eight bandages were retrospectively analyzed. Shortening, displacement, and butterfly fragment length were measured radiographically at diagnosis. The patients were evaluated at Weeks 4, 6, 12, and 24 after injury. The patients were divided into three groups: patients with unionized fractures, patients with delayed union, and patients with nonunion. In patients where radiographic union was not observed after four to six weeks, the figure-of-eight bandage treatment was continued. Delayed union was defined as the absence of radiographic signs of fracture consolidation within 12 weeks, and nonunion as the absence of fracture consolidation within 24 weeks.

Fractures in 13 (42%) patients healed within 12 weeks, 10 (32.2%) patients had delay healing between 12 and 24 weeks, and eight (25.8%) patients had nonunion. The median shortening was 18.37 (range, 3 to 42.9) mm, while median displacement ratio and butterfly fragment length were 125% (range, 83 to 93%) and 21.7 (range, 12 to 47.2) mm, respectively. No statistically significant difference in shortening was observed among the three groups (p=0.71). There was a significant difference in the amount of displacement between the healed fractures and delayed union groups (p=0.006) and the healed fractures and nonunion groups (p=0.002). There was also a significant difference in the butterfly fragment length between the healed fractures and nonunion groups (p=0.008). For each 1% increase in displacement, the relative risk of delayed union increased by 8%, and the risk of nonunion increased by 10%. A cut-off value of 125% optimally distinguished healed from unhealed fractures (area under the curve [AUC]=0.874). For differentiating delayed union from nonunion, the optimal threshold was 142.5% (AUC=0.713), indicating moderate diagnostic performance.

In adult clavicle shaft fractures with butterfly fragments, butterfly fragment length and clavicle shortening did not affect bone healing. In contrast, displacement was the only significant predictor of impaired bone healing.