[Preliminary clinical research with rib cartilages anomalies in patients with microtia].

Objective: To investigate the characteristics and constituent ratio of rib cartilages anomalies in patients with microtia.

Methods: We conducted a retrospective study of the clinical and imaging data of 230 consecutive patients with microtia from November 2014 to September 2015 in Plastic Surgery Hospital. Pearson x2 test and Spearman analysis were used to analyze the relationship between microtia and rib cartilages anomalies.

Results: A total of 75 cases (32.6％) were documented with rib cartilages anomalies, including 4 cases (1.7％) with numerical variations,16 cases (7.0％) with structural changes,63 cases (27.4％) with abnormal articulations and 8 cases with two types of anomalies. Abnormal attachment to the sternum of the eighth rib cartilages was observed frequently (18.7％),whereas 10 cases (4.7％) with the seventh rib cartilages failing to attach to the sternum. The constituent ratio of rib cartilages anomalies in microtia Ⅰ, Ⅱ, and Ⅲ was 11.5％ (3/26),32.8 ％ (58/177) and 51.9％ (14/27), respectively. The patients with microtia Ⅲ were observed to have a higher ratio of rib cartilages anomalies than those with microtia Ⅱ. Similarly, patients with microtia Ⅱ were found to have a higher ratio of rib cartilages anomalies than those with microtia Ⅱ (P =0.007).

Conclusions: The constituent ratio of rib cartilages anomalies is high in patients with microtia. And the constituent ratio is varied with the grades of microtia. A higher ratio of costal cartilages anomalies is present in patients with a more serious grade of microtia.