Clinical outcome of AO/OTA type C fracture of the distal humerus using the expanded paratricipital approach and cadaveric comparison of the exposure of the paratricipital and expanded paratricipital approaches to the distal humerus.

Background: We investigated the overall clinical outcome of the expanded paratricipital approach in complex articular fractures of the distal humerus and the effect of lack of visualization in the surgical field. In addition, we performed a cadaveric study to investigate the expansion or limitation of articular access in the expanded paratricipital approach.

Methods: Forty-one AO/OTA type 13C fracture cases treated using the expanded paratricipital approach at a single trauma center from 2013 to 2017 were enrolled in this study. We evaluated the overall clinical outcome and analyzed the effect of lack of visualization in the surgical field with the expanded paratricipital approach by comparing outcomes between 2 groups classified by the location of the main articular fracture (group 1, limited visualization; group 2, without limited visualization). The length of inaccessible and accessible articular segments were analyzed using 40 matched-pair elbows.

Results: The average duration of follow-up was 15.1 months. All fractures (type C1 in 11 cases, type C2 in 21, and type C3 in 9) were radiologically healed at 3.2 months after surgery. No cases required additional surgery because of implant irritation. The average Mayo Elbow Performance Score was 90.5. The mean Disabilities of the Arm, Shoulder and Hand score was 18.5. Among the 41 cases, the limited visualization group (group 1, n = 21) had a longer surgical time and higher percentage of nonanatomic reduction than group 2. Although the expanded paratricipital approach allowed more articular exposure than the conventional approach, there was still a 20mm inaccessible articular segment (30% of transepicondylar width) in cadaveric dissection.

Conclusions: The expanded paratricipital approach can be used in type C1, type C2, and selective type C3 articular fractures of the distal humerus with favorable results. Relative to surgical times and achieving anatomic reduction, it is more successful in a fracture with a main articular fragment and with good visualization.