Intradural extramedullary tumor location in the axial view affects the alert timing of intraoperative neurophysiologic monitoring.

OBJECTIVE: Intraoperative neurophysiologic monitoring (IONM) reportedly helps prevent postoperative neurological complications following high-risk spinal cord surgeries. There are negative and positive reports about using IONM for intradural extramedullary (IDEM) tumors. We investigated factors affecting alerts of IONM in IDEM tumor surgery. METHODS: We analyzed 39 patients with IDEM tumors who underwent surgery using IONM at our hospital between January 2014 and March 2021. Neurological symptoms were evaluated pre- and postoperatively using the manual muscle test (MMT). All patients were evaluated to ascertain the tumor level and location in the axial view, the operative time, intraoperative bleeding volume, and histological type. Additionally, the intraoperative procedure associated with significant IONM changes in transcranial electrical stimulation muscle-evoked potential was investigated. RESULTS: There were 11 false-positive and 16 true-negative cases. There was one true-positive case and one false-negative case; the monitoring accuracy achieved a sensitivity of 50%, a specificity of 59%, a positive predictive value of 8%, and a negative predictive value of 94%. In the 22 alert cases, if the tumor was located anterolateral in the axial view, alerts were triggered with a significant difference (p = 0.02) during tumor resection. Alerts were generated for fifteen patients during tumor resection; nine (60%) showed waveform improvement by intervention and were classified as rescue cases. CONCLUSION: Alert is probably triggered during tumor resection for anterolaterally located tumors. Alerts during tumor resection procedures were more likely to be rescued than other procedures in IDEM tumor surgery.

Treatment of Capitellum and Trochlea Fractures Using Headless Compression Screws and a Combination of Dorsolateral Locking Plates.

Introduction This study aimed to evaluate the clinical outcomes of 16 patients with capitellum and trochlea fractures that were treated using isolated headless compression screws or a combination of dorsolateral locking plates and anterior-to-posterior screws. We also investigated the presence of lateral epicondyle fragments because this fragment is especially important when making decisions regarding the surgical approach and implants. Materials and methods We conducted a retrospective analysis of 16 patients with capitellum and trochlea fractures. Clinical, radiographic (based on CT scans), and elbow-specific outcomes, including the Mayo Elbow Performance Index (MEPI), were evaluated at a mean of 23.5 months postoperatively. Results The average MEPI scores in patients with Dubberley type A (non-posterior comminution) and type B (posterior comminution) fractures were 88 and 78, respectively (p=0.08). Headless compression screws were used in 10 cases of type A fracture and one case of type B fracture. A combination of dorsolateral locking plates and anterior-to-posterior screws was used in five cases of type B fracture. Hardware loosening was seen in one case of type B fracture with isolated screw fixation. The presence of a lateral epicondyle fragment was significantly associated with the type B group (6/6 patients; 100%). In contrast, patients in the type A group rarely had posterior comminution of the lateral epicondyle fragment (2/10 patients; 20%). Conclusions Capitellum and trochlea fractures with posterior comminution, which typically presented with lateral epicondylar fragments, were safely and effectively treated with a combination of dorsolateral locking plates and anterior-to-posterior screws through lateral approaches. Cases without posterior comminution were treated with headless compression screws with no complications. The Dubberley classification system provides helpful information to determine the fixation strategy.

Iliac intramedullary stabilization for Type IIIA fragility fractures of the pelvis.

There have been few reports on fixation of Rommens classification Type IIIA fragility fractures of the pelvis (FFPs). Here, we present our less invasive surgical technique, called iliac intramedullary stabilization (ILIS), for the internal fixation of Type IIIA FFPs. The technique involves a closed reduction, termed the femur internal rotation reduction method (FIRM), whereby the fracture fragments are repositioned using lateral rotators by internally rotating the femur while the patient is in the prone position. Two iliac screws are inserted on the ilium bilaterally via the supra-acetabular bone canal during FIRM and connected with two transverse rods and two cross connectors. We refer to this internal fixation procedure as ILIS. We retrospectively recruited patients with Type IIIA fractures, treated using this procedure, at our institute between October 2017 and October 2019. We evaluated operative and post-operative outcomes. We enrolled 10 patients (9 women and 1 man; mean age, 85.2 years) who were followed up for over 6 months. All patients suffered FFPs after falling from a standing position. The mean operative time was 145.1 (range, 94-217) minutes, and the mean blood loss was 258.5 (range, 100-684) ml. All patients were allowed full weight bearing from post-operative day 1. All patients achieved bone union and regained their pre-injury walking ability at 6 months after surgery without evident secondary displacement. In conclusion, our ILIS technique allows less invasive internal fixation of Type IIIA FFPs with adequate stability for full weight bearing from post-operative day 1.