RESUMEN
BACKGROUND: Chronic ankle instability is frequent complication following ankle sprains. Anatomical reconstruction of the anterior talofibular ligament (ATFL) and the calcaneofibular ligament (CFL) with a gracilis autograft is a validated reconstruction technique. The signal-to-noise quotient ankle (SNQA) score evaluates graft maturation with MRI and has been shown to be reproducible and reliable. The goal of this study was to evaluate the process of ligamentization of the anatomical reconstruction of the ankle using the SNQA. The hypothesis was that the SNQA signal of the ATFL and the CFL would decrease over time. METHODS: A prospective cohort of patients who underwent arthroscopic anatomical ATFL-CFL reconstruction was included. All patients underwent a follow-up MRI examination 3, 6. and 12 months after surgery and the SNQA score was determined. RESULTS: Twenty consecutive patients were included. The SNQA score decreased significantly over time for the ATFL (p = 0.001), the CFL (p < 0.001) and for the fibular bone tunnel-graft interface (p = 0.02). The SNQA scores of the ATFL were significantly higher than those of the CFL at 3 months (p = 0.01), 6 months (p = 0.003) and 12 months (p < 0.001), and then those of the fibular tunnel-graft interface at 12 months (p = 0.003). There was no difference in the SNQA score between the CFL and in the fibular graft-bone tunnel interface at any of the follow up periods. CONCLUSION: There is a process of graft maturation following anatomical ATFL and CFL reconstruction over time, which is faster for the CFL than for the ATFL during the first year. LEVEL OF EVIDENCE: II.
RESUMEN
BACKGROUND: The aim of this cadaver study was to evaluate an original technique for measuring posterior tibial translation based on an angle value instead of a distance value, with and without posterior stress application. It was hypothesized that an angle measurement of the posterior tibial translation would confirm the presence of a PCL tear with the knee flexed and completely extended. METHOD: Using fresh cadavers, a set of strict lateral views were taken by fluoroscopy with the knee at 0°, 45° and 90° flexion on the intact knee and after transecting the PCL. The primary endpoint was the change in the posterior translation measured using a new technique, the ABC angle. This measurement was compared to the conventional posterior translation distance measurement with and without a posterior stress placed on the knee. RESULTS: Application of a posterior stress revealed clear changes in posterior translation after PCL transection with the knee at 0° for the angle technique and at 45° and 90° for the two techniques (p < 0.05). Contrary to the reference method, the ABC angle method found a statistically significant difference in posterior translation with the knee in extension. CONCLUSION: Our technique provides a reliable radiographic measurement of posterior translation with the knee in extension, which should make it easier to acquire radiographs in patients who have pain with knee flexion. This angular measurement also has the advantage of not needing length calibration contrary to the reference technique. LEVEL OF EVIDENCE: IV.