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

Purpose: 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.

Methods: 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.

Results: 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.

Conclusions: 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.

Clinical relevance: Various techniques have been described for PLC reconstruction. However, no study has comprehensively compared the biomechanical properties of these reconstructions with one another.