Long dorsal "Y-shaped" plate for distal diaphyseal humeral fractures

Osteosynthesis of distal diaphyseal humeral fractures is challenging, especially if there is a metaphyseal extension of the fracture line with a butterfly third fragment or if the fracture is bifocal. These fractures put the radial nerve at risk at the time of the fracture and during surgery. We hypothesize that ORIF with a long dorsal Y-plate matching the dorsal aspects of the humeral diaphysis and of the two metaphyseal columns would provide a reliable method of fixation for distal diaphyseal humeral fractures even when there is a metaphyseal extension or bifocal component.

Between 2015 and 2019, 17 distal diaphyseal humeral fractures in 17 consecutive patients (14 men, 3 women, mean age 38 years) were operated on with a long "Y-shaped" dorsal plate. There were two bifocal fractures and 11 diaphyso-metaphyseal fractures with butterfly fragments. All 17 patients could be retrospectively followed up clinically and radiographically at a mean follow-up of 25 months (min 4, max 40). Clinical charts included VAS pain, elbow range of motion, QuickDASH, MEPS and subjective elbow value.

Bone healing was observed in all cases. Five patients (29%) had a pre-operative radial nerve palsy. All pre-operative radial nerve palsies but one recovered spontaneously. One complete radial nerve palsy that was not present before the operation was observed after surgery. It recovered spontaneously in four months. One case of post-operative elbow stiffness required a revision. Only one case (5%) showing a complication directly related to the plate (secondary displacement) required revision. Mean post-operative elbow flexion was 134°. Extension deficit averaged 13°. Subjective elbow value, QuickDASH and MEPS averaged respectively 81%, 19 points and 92 points.

Currently available plates (long dorsal straight, short dorsal "Y-shaped", long lateral) may have limitations in terms of screw purchase or biomechanical efficiency when ORIF of distal diaphyseal humeral fractures is considered. A long dorsal "Y-shaped" plate is a new alternative which may be successfully used even in the most difficult cases.

Our study suggests that a long dorsal "Y-shaped" plate is suitable for distal diaphyseal humeral fractures especially when there is a metaphyseal bifocal or third fragment component.