Is bioabsorbable screw an alternative choice for displaced medial epicondylar fractures in adolescents: A comparative study of metallic cannulated lag screw versus bioabsorbable screw

In adolescent patients, cannulated lag screw (CLS) is a widely accepted choice for fixation of the medial epicondylar fracture of the humerus (MEFH). Absorbable implants, including rod, screw, and mini-plate, have been reported in children. However, to the best of our understanding, this study is the first head-to-head comparative study of CLS versus bioabsorbable screw (BS) in the treatment of MEFH. Patients of MEFH operated at our institute, from January 2010 to January 2016, were reviewed retrospectively. The patients were divided into 2 groups, the CLS group and the BS group, as per the type of implant the patient received. The CLS group consisted of 35 patients, whereas the BS group consisted of 30 patients. Demographic data, including sex, age at the time of surgery, operated side, and implant material, were collected from the hospital database. Elbow range of motion (ROM), radiographic manifestation was recorded during the out-patient visit. The elbow joint function was evaluated according to the Broberg and Morrey elbow scale and Mayo elbow performance index score. Thirty patients, including 18 males and 12 females, were included in the CLS group, whereas 35 patients, including 21 males and 14 females, were included in the BS group. At 6-month follow-up, elbow range of motion, Broberg and Morrey elbow scale and Mayo elbow performance index scale showed no significant difference between the 2 groups. The carrying angle was within the normal range in both groups. There was no nonunion or malunion in either group. The rate of hypoplasia or hyperplasia was low in both groups, 3.3% in CLS and 2.9% in BS. The rate of implant prominence was significantly higher in the CLS group (33.3%) than BS (0%). Both CLS and BS are safe and effective choices for displaced MEFH in adolescents. The BS can produce a satisfactory clinical outcome and is comparable to the CLS. Besides, the BS has the advantage of not needing second surgery for implant removal.