Supracondylar humerus fractures are common fractures in children. The standard treatment for displaced supracondylar fractures of the humerus is closed reduction and percutaneous pin fixation. For closed reduction, the surgery’s experience is very important . Saarinen, A.J reported that there is a significant difference in outcome of surgical treatment for supracondylar humerus fractures between the surgical specialties. In the process of closed reduction, the small bone fragments usually are not easy to get an anatomical reduction especially for those less experienced surgeons. These bone fragments will be presented on the postoperative X ray film and cause the parents' worries. From January 2015 to January 2018, there were 460 cases of pediatric supracondylar humerus fractures treated in our center, and 12 (2.6%) patients who received CRPP treatment had bone fragments on postoperative X ray film. Patients treated with open surgery didn’t have any unsatisfactory fragments on postoperative X ray film, for it could be well managed during the operation.
Mostly, the supracondylar humerus fractures are extension type and occurring as a result of fall on an outstretched hand . Patients with supracondylar humerus fractures enrolled in our study were all extension fracture classified as Gratland type III. The bone fragments on X ray film all lay anterior to the humerus, without bone fragments on posterior side. It may be related to the mechanism of injury or the procedure of reduction, but exact mechanism is still unclear. In our study, all the bone fragments were very close to the humerus on X ray film. It might mean that there was still some periosteum connected between the fragments and humerus, which would be beneficial to the union of the fragments. While we had no evidence to prove it due to the closed reduction procedure.
Although complications of supracondylar fractures are common in the pediatric population, the long-term outcome and function is good if the fracture is appropriately diagnosed and treated . Many of the associated complications either are self-limited or are amenable to functional repair with surgical intervention. In our study, the small fragments on X ray film after CRPP treatment all “disappeared”, either be absorbed or fusion to humerus. But we didn’t think all the fragments left after operation would disappear, in case of infection, unsatisfactory pins fixation or lose of reduction, there might be a problem. For the large fragments or free fragments far away from humerus, we also preferred open surgery for an anatomical reduction. While, how to define the size of “small fragment” or totally free fragment usually depended on the surgeons, which was also a limitation of our study. A computed tomography (CT) scan may be helpful for the accurate assessment of the fragments’ size, but whether there is such a need remains to be discussed.
For those severely displaced supracondylar fractures, there is still a difference in opinion among authors whether utilizing closed reduction or open reduction procedure . Open reduction with percutaneous pinning is an accepted treatment for severely displaced, irreducible fractures of the distal humerus [11–12], which also has several complications like infection, ROM limitation and scarring . There is no research to prove that withier we should have an open procedure for supracondylar humerus fracture with such small fracture anterior to the humerus. In our study, the small fragments left after closed reduction is not an indication for open surgery, which may be absorbed or healing. But more research is needed to support it.
Other limitations of our study were the small number of cases and a short follow-up period. In addition, this study was retrospective. Therefore, we could not draw any firm conclusions. A large, prospective study is needed.