RESUMO
OBJECTIVE: To determine the visible size of the distal humeral articular surface by using a novel combined medial-lateral approach as an alternative method of surgical treatment for intra-articular distal humeral fractures. METHODS: In this anatomical study, 12 adult fresh-frozen cadaveric elbows were randomly divided into a medial-lateral group and an olecranon osteotomy group, with 6 in each group. In the medial-lateral group, a medial approach was first used, and then a lateral approach. The sizes of the distal humeral articular surface exposed by each incision and the joined size were measured and calculated. In the olecranon osteotomy group, a posterior olecranon osteotomy approach was applied, and the maximal visible sizes of the articular surface were marked and calculated. Ratios of the maximal sizes of the distal humeral articular surface of the two approaches were compared. RESULTS: In the medial-lateral group, the medial approach could expose 2/5 of the medial trochlea and 1/3 of the capitellum, while the mean visible size of the distal humeral articular surface was 6.8 cm2 , 34.8% of the entire surface; the lateral approach can expose 3/7 of the capitellum and 1/4 of the medial trochlea, while the mean visible size of the distal humeral articular surface was 6.7 cm2 , 33.9% of the whole surface; for the combined medial-lateral approach, the mean scope exposed of the medial and lateral visible articular surface was 38.2% and 43.1%, respectively. Meanwhile, in the olecranon osteotomy group, the posterior olecranon osteotomy was found to expose most of the posterior distal humeral articular surface, except for 1/3 of the anterior trochlea and 1/4 of the anterior capitellum, and the visible range of articular surface was 65.3%. The combined medial-lateral approach exposed 9.2 cm2 in total, 46.9% of the whole distal humeral articular surface, which averaged 19.6 cm2 . However, the visible size of the distal humeral articular surface for the olecranon osteotomy approach was 13.7 cm2 , 63.1% of the entire distal humeral articular surface, which averaged 21.3 cm2 . There was a significant difference observed between the medial-lateral group (46.9%) and the olecranon osteotomy group (63.1%) for the maximal visible size of the distal humeral articular surface (t = 7.201, P = 0.001). CONCLUSIONS: The combined medial-lateral approach can expose 46.9% of the distal humeral articular surface, concentrating on the anterior part, so it can be recommended to treat intra-articular fractures with a simple pattern in the posterior with the anterior side of the distal humerus less comminuted.