[Articular coronal fractures of the distal humerus].

INTRODUCTION

The vague term of capitellar fractures is still frequently used to designate articular coronal fractures of the distal humeral epiphysis. The use of eponyms for their descriptions may cause confusion. Recent publications describe a wide variety of fracture types and recommend new classifications based on the operative findings. We report our results of surgical treatment of 12 cases of these fractures in comparison to recent series of the literature.

METHODS

Twelve patients (seven female and five male with a mean age of 31 years and 6 months) have been treated for articular coronal fractures of the distal humeral epiphysis between 1994 and 2004. A retrospective analysis of the radiographs and the operative notes permits their differentiation into 3 types according to the classification of Dubberley et al. (2006): ten fractures of type 1, one fracture of type 2 and one fracture of type 3. All fractures underwent open reduction and internal fixation, except for one case, which was initially missed and operated, therefore, by excision of the articular fragment with a delay of 6 weeks. All patients were clinically evaluated according to the index of performance of Morrey et al. (1993). In addition, a radiological assessment based on the scale of Knirk and Jupiter (1986) for elbow osteoarthritis was performed.

RESULTS

The mean follow-up was 9 years. The clinical evaluation showed seven excellent results (six cases of type 1 and one case of type 3 with a score of 100 points for each one), two good (type 1 with 80 and 85 points of respective scores) and three fair (two cases of type 1 with 65 and 60 points of respective scores and one case of type 2 with a score of 65 points). The radiological evaluation showed seven elbows of grade 0 (six cases of type 1 and one case of type 3), four elbows of grade 1 (type 1) and one elbow of grade 2 (type 2).

DISCUSSION

Articular coronal fractures of the distal humerus are rare. The classification of Dubberley et al. (2006) [7] is comprehensive and allows inclusion of all varieties of these fractures. In addition, it is the only one that indicates the surgical approach according to the fracture type. However, to do so, a preoperative CT-scan is highly recommended. The more the fracture line extends medially to involve the trochlea (types 2 and 3), the less a lateral approach is sufficient and the more a combined lateral and medial or a posterior transolecranon approach is mandatory. An internal fixation using conventional small fragment screws inserted from posterior to anterior is feasible when the articular fragment has a sufficient subchondral bone thickness. A direct anteroposterior fixation is better achieved using headless screws buried beneath the cartilaginous surface; it is particularly helpful when the articular fragment has a thin sub-chondral cancellous bone component. Excision is reserved for comminuted fractures, those not amenable to fixation, very thin or osteoporotic fragments, and for the late diagnosed fracture.