Anatomic Fibular-Based Posterolateral Corner Reconstruction With 2 Femoral Tunnels Shows Lowest Residual Laxity With External Rotation and Varus Stresses: A Systematic Review and Network Meta-analysis of In Vitro Biomechanical Studies.

Abstract

To perform a systematic review and network meta-analysis of in vitro cadaveric, biomechanical studies evaluating described techniques for posterolateral corner (PLC) reconstruction, including fibular- and tibiofibular-based techniques. The PubMed/MEDLINE, Embase, and Cochrane Library databases were searched in December 2023 for cadaveric studies evaluating PLC reconstruction. After a descriptive summary, a series of frequentist network meta-analyses comparing (1) nonanatomic fibular-based (single femoral tunnel), (2) anatomic fibular-based (double femoral tunnel), and (3) anatomic tibiofibular-based PLC reconstructions with the intact knee were performed for both external rotation (ER) and varus laxity from 0° to 90° of knee flexion. Pooled treatment estimates were calculated as mean differences (MDs) with 95% confidence intervals (CIs) using random-effects models. A total of 31 studies were included. Nonanatomic fibular-based reconstructions showed increased ER laxity compared with the intact state between 30° and 90° of flexion (MD, 1.66° [95% CI, -0.27° to 3.59°] at 0° [P = .093]; MD, 2.29° [95% CI, 0.44° to 4.13°] at 30° [P = .015]; MD, 3.04° [95% CI, 0.95° to 5.12°] at 60° [P = .004]; and MD, 4.30° [95% CI, 1.41° to 7.19°] at 90° [P = .004]). The anatomic fibular- and tibiofibular-based reconstructions restored ER stability at all flexion values (except at 0° for tibiofibular based). All 3 reconstructions restored varus stability compared with the intact state in all scenarios except the anatomic fibular-based techniques at 0° (MD, 0.85° [95% CI, 0.06° to 1.63°]; P = .034). Across the assessed ER and varus laxity states, the anatomic fibular-based reconstruction was ranked "best" in 5 of 8 scenarios. PLC reconstructions using nonanatomic fibular-based techniques showed increased residual laxity in ER from 30° to 90° of knee flexion. Conversely, anatomic fibular- and tibiofibular-based reconstructions showed ER and varus laxity similar to that in the intact knee state across most of the assessed knee flexion values. Various techniques have been described for PLC reconstruction. However, no study has comprehensively compared the biomechanical properties of these reconstructions with one another.