Rationale: Because of the complicated anatomy and considerable change in size and morphology with age in teenagers, the appropriate internal fixator of coronal shear fracture of distal humerus is difficult to choose, and therefore, the fixation of this kind of fracture is difficult and controversial. Furthermore, distal humeral fractures in teenagers often involve the epiphysis, the rigid fixation of fracture and the simultaneous minimally invasive and protection of the epiphysis are contradictory. Coronal shear fractures of the distal humerus in teenagers are great challenge for orthopedic surgeons. Three-dimensional (3D) printing designed customized plate in the treatment of coronal fracture of distal humerus in teenager is a potential satisfactory choice in the treatment of the complex fractures. Patient concerns: A teenager suffered from an elbow joint injury due to a fall while running, resulting in pain, swelling and limited movement of the elbow joint. The epiphyseal has not closed in this patient, conventional surgical procedures have great traumatic and invasive, and to some extent affect bone growth in children. Diagnoses: Coronal shear fracture of right distal humerus according to computed tomography scan. Interventions: We used 3D printing technology to design an internal fixation device for this patient, which was to treat the distal humeral coronal shear fracture in a teenager via an anterior approach to the elbow joint, and finally the child was instructed to perform immediate postoperative functional exercises and rehabilitation. Outcomes: Radiographic reexamination performed 1 day and 2 month after the operation showed that the internal fixation was in good position, no fracture displacement. the patient was instructed to perform active flexion and extension internal and external rotation of the right elbow 6 weeks postoperatively. The Mayo elbow function score was excellent 5 months postoperatively. The range of motion of the elbow was (15°–130°) Lessons: The treatment of coronal shear fractures of the distal humerus in teenager is controversial at present. This report 3D printing technology designed customized plate in treatment of such fractures showed satisfactory results, which provides a feasible method for the treatment of fractures without suitable internal fixation devices in the future.

Rationale: Clavicle fractures are common, accounting for 2.6 to 4% of all fractures, which typically result from direct injuries, including direct force on the shoulder after falling. However, bipolar clavicle fractures are rare, accounting for only 2.8% of all clavicle fractures, and their injury mechanism is speculated to evolve from two independent and continuous forces affecting the clavicle. Due to its low incidence, there is great controversy regarding the treatment of this fracture, as there is no relevant treatment standard or guideline to date. Patient concerns: In this case report, we describe a rare case of bipolar clavicle fracture in a 76-year-old man with multiple systemic fracture complications due to a traffic injury. He presented with limited shoulder function and movement upon arrival in the emergency room. Diagnosis: Bipolar clavicle fracture in the right shoulder (Robinson type 1B2, Robinson type 3B2) Interventions: We performed trans-sternoclavicular locking plate and lateral clavicular hook plate treatments and instructed patients to perform reasonable postoperative functional exercises. Outcomes: Three months postoperatively, the pain was almost completely relieved with a DASH score of 40.0. Furthermore, radiographic examination of the clavicle showed satisfactory fracture healing. The patient had no further demands for shoulder function and no irritative symptoms of internal fixation and refused to undergo a second operation. The patient had a satisfactory prognosis after the treatment. Lessons: The treatment of bipolar clavicle fractures remains controversial. This study provides evidence of a feasible method to treat bipolar clavicle fractures: trans-sternoclavicular locking plate and lateral clavicular hook plate treatment.