Mediolateral shortening is a risk in treatment of clavicle shaft fracture, and can lead to scapular dyskinesis and shoulder dysfunction. Many studies advocated surgical treatment if shortening exceeds 15mm.

Clavicle shaft shortening of less than 15mm has negative impact on shoulder function at more than 1 year's follow-up.

A retrospective case-control comparative study was performed, with assessment by an independent observer. Clavicle length was measured on frontal radiographs showing both clavicles, and the ratio between the healthy and affected sides was calculated. Functional impact was assessed on Quick-DASH. Scapular dyskinesis was analyzed by global antepulsion on Kibler's classification. In total, 217 files were retrieved for a 6-year period. Clinical assessment was performed for 20 patients managed non-operatively and 20 patients managed by locking plate fixation, at a mean 37.5months’ follow-up (range: 12–69months).

Mean Quick-DASH score was significantly higher in the non-operated group: 11.363 [0–50] versus 2.045 [0–11.36] (p=0.0092). Pearson ρ correlation between percentage shortening and Quick-DASH score was −0.3956 [95% CI: −0.6295; −0.0959] (p=0.012). Clavicle length ratio differed significantly between groups: operated group, +2.2% [−5.1%; +17%] for 0.34cm; non-operated group, −8.28% [−17.3%; −0.7%] for 1.38cm (p<0.0001). Shoulder dyskinesis was significantly more frequent non-operated patients: 10 versus 3 (p=0.018). A threshold of 1.3cm shortening was found for functional impact.

Restoring scapuloclavicular triangle length is an important aim in management of clavicular fracture. Surgery by locking plate fixation is therefore to be recommended in case of>8% radiological shortening (1.3cm) to avoid medium- and long-term complications in shoulder function.

III; case-control study.