Background: Training beginners of the pedicle screw instrumentation technique in the operating room is limited because of issues related to patient safety and surgical efficiency. Three-dimensional (3D) printing enables training or simulation surgery on a real-size replica of deformed spine, which is difficult to perform in the usual cadaver or surrogate plastic models. The purpose of this study was to evaluate the educational effect of using a real-size 3D-printed spine model for training beginners of the free-hand pedicle screw instrumentation technique. We asked whether the use of a 3D spine model can improve (1) screw instrumentation accuracy and (2) length of procedure. Methods: Twenty life-size 3D-printed lumbar spine models were made from 10 volunteers (two models for each volunteer). Two novice surgeons who had no experience of free-hand pedicle screw instrumentation technique were instructed by an experienced surgeon, and each surgeon inserted 10 pedicle screws for each lumbar spine model. Computed tomography scans of the spine models were obtained to evaluate screw instrumentation accuracy. The length of time in completing the procedure was recorded. The results of the latter 10 spine models were compared with those of the former 10 models to evaluate learning effect. Results: A total of 37/200 screws (18.5%) perforated the pedicle cortex with a mean of 1.7 mm (range, 1.2–3.3 mm). However, the latter half of the models had significantly less violation than the former half (10/100 vs. 27/100, p < 0.001). The mean length of time to complete 10 pedicle screw instrumentations in a spine model was 42.8 ± 5.3 min for the former 10 spine models and 35.6 ± 2.9 min for the latter 10 spine models. The latter 10 spine models had significantly less time than the former 10 models (p < 0.001). Conclusion: A life-size 3D-printed spine model can be an excellent tool for training beginners of the free-hand pedicle screw instrumentation.

Open reduction and plate fixation is the standard operative treatment for displaced midshaft clavicle fracture. However, sometimes it is difficult to achieve anatomic reduction by open reduction technique in cases with comminution. We describe a novel technique using a real-size three dimensionally (3D)-printed clavicle model as a preoperative and intraoperative tool for minimally invasive plating of displaced comminuted midshaft clavicle fractures. A computed tomography (CT) scan is taken of both clavicles in patients with a unilateral displaced comminuted midshaft clavicle fracture. Both clavicles are 3D printed into a real-size clavicle model. Using the mirror imaging technique, the uninjured side clavicle is 3D printed into the opposite side model to produce a suitable replica of the fractured side clavicle pre-injury. The 3D-printed fractured clavicle model allows the surgeon to observe and manipulate accurate anatomical replicas of the fractured bone to assist in fracture reduction prior to surgery. The 3D-printed uninjured clavicle model can be utilized as a template to select the anatomically precontoured locking plate which best fits the model. The plate can be inserted through a small incision and fixed with locking screws without exposing the fracture site. Seven comminuted clavicle fractures treated with this technique achieved good bone union. This technique can be used for a unilateral displaced comminuted midshaft clavicle fracture when it is difficult to achieve anatomic reduction by open reduction technique. Level of evidence V.

Background: Chronic ankle instability with generalized joint hypermobility (GJH) is considered a contraindication for the modified Broström procedure. The most widely accepted definition of GJH is a Beighton score of ≥4 on a 9-point scale. However, it is not clear whether this criterion can be applied to determine the GJH that would lead to a poor outcome after a modified Broström procedure. Some of the previous studies that report unfavorable outcomes do not specify the tests or cutoff scores used to determine the GJH, and, in fact, some of the patients with GJH in these studies had good outcomes. Hypothesis: The modified Broström procedure results in satisfactory outcomes in patients who have chronic ankle instability with GJH if the contralateral uninjured ankle shows a normal varus talar tilt and anterior talar translation during stress tests. Study Design: Case series; Level of evidence, 4. Methods: Modified Broström procedure was performed in 32 patients with chronic ankle instability with GJH if the contralateral uninjured ankle showed a normal varus talar tilt and anterior talar translation on stress tests. The mean patient age at surgery was 21.7 years, and the mean follow-up duration was 27.4 months. Results: The Karlsson-Peterson ankle score significantly improved from a mean ± SD of 63.6 ± 7.1 preoperatively to 90.4 ± 6.7 at the final postoperative follow-up ( P < .001). Sixteen patients were very satisfied with the results, 10 patients were satisfied, 3 patients rated their satisfaction as fair, and 1 patient was dissatisfied with the results. Nine patients sustained ankle sprains after the surgery, 6 of which were mild sprains. Although 3 of these 9 patients had a mechanically unstable ankle on stress radiographs, they were satisfied with the postoperative results. None of the patients required a reoperation. Conclusion: GJH was not a contraindication for the modified Broström procedure if the contralateral uninjured ankle showed a normal varus talar tilt and a normal anterior talar translation on stress tests. Further studies are needed to better define GJH affecting the ankle.