Posterolateral Corner Reconstruction Using the Single Fibular Sling Method for Posterolateral Rotatory Instability of the Knee

Abstract

Background: Recently, posterolateral corner (PLC) reconstruction techniques have been developed based on an anatomic study of cadaveric dissections. However, the best operative method for various anatomic reconstructions remains controversial. Hypothesis: The anatomic single fibular sling method for PLC reconstruction would be sufficiently strong to control posterolateral rotatory instability without an additional tibial sling. Study Design: Case series; Level of evidence, 4. Methods: This retrospective cohort study analyzed 60 knees in 60 patients who underwent anatomic PLC reconstruction using the single fibular sling method with a tibialis anterior allograft, with a minimum follow-up period of 2 years. Ninety percent of the patients had concomitant reconstruction of one or both cruciate ligaments. Preoperative and postoperative dial test, varus stress test, and subjective clinical outcomes including Lysholm score, International Knee Documentation Committee (IKDC) subjective scores, and stress radiographs, including varus and posterior stress, were compared. In addition, intraoperative arthroscopic findings were analyzed. Results: The mean length of clinical follow-up was 35.6 months (range, 24-65 months). Forty-two (70%) patients showed no rotational instability postoperatively. Varus laxity improved, with 96.7% of the patients assessed as grade 0 or 1. The mean side-to-side difference in varus stress test was reduced from 2.32 ± 1.33 mm preoperatively to 0.37 ± 1.48 mm postoperatively. Posterior stress radiography in combined posterior cruciate ligament reconstruction showed a mean posterior tibial translation of 14.7 ± 2.83 mm preoperatively and 4.06 ± 1.40 mm at final follow-up. The Lysholm and IKDC subjective scores improved from 52 ± 6.7 to 87.7 ± 12.3 and from 44.8 ± 6.3 to 77.6 ± 14.2 ( P < .001), respectively. There were no significant differences in clinical outcome or varus laxity between isolated PLC and combined injuries. Conclusion: Anatomic PLC reconstruction using a single fibular sling method is an effective and relatively simple procedure for most patients with posterolateral rotatory instability, with the exception of those with severe multiple injuries.