In an in-vitro, cadaveric study of combined PCL/PLC injuries, it has been demonstrated that extra-articular augmentation of intra-articular PCL reconstructions is necessary for the restoration of normal posterior, varus and external rotation laxities. Also, it has been shown that there is little advantage of a double-bundle PCL reconstruction over a single-bundle reconstruction when extra-articular augmentation is used. Augmentation of intra-articular PCL reconstructions by extra-articular reconstructions of the PLC is needed to restore normal posterior, varus and external laxities to the combined PCL/PLC injured knee. The question arises whether an augmented, double-bundle intra-articular PCL reconstruction is necessary, or is an augmented, single-bundle, intra-articular reconstruction sufficient to reconstruct the PCL/PLC injured knee. Simulated anterior/posterior, varus/valgus and internal/external rotation stress tests were conducted on twelve, fresh, frozen, human cadaveric knees at flexion angles of 90°, 60°, 30° and at full extension, before and after cutting of the PCL/PLC, and following single and double bundle reconstructions augmented by Larson extra-articular reconstructions. Neither intra-articular reconstruction alone reduced the abnormal varus or external rotations seen in the PCL/PLC deficient knee. Both augmented, intra-articular reconstructions restored posterior laxity at 30 degrees of flexion and at full extension; varus laxity at 60 and 90 degrees of flexion; and external rotation laxity at all tested angles of flexion, to near-normal values. Posterior laxity at 60 degrees of flexion, and varus laxity at 30 degrees of flexion and at full extension, were restored to near normal values only by the augmented, double-bundle reconstruction. Neither augmented, intra-articular reconstruction restored near normal posterior laxity at 90 degrees of flexion. Given the substantial correction of the varus and external rotation laxities, as well as the posterior laxity, of the combined PCL/PLC injured knee afforded by the augmented, single-bundle reconstruction, the few occurrences of superiority of the augmented, double-bundle reconstruction provide limited gains in the face of the much greater complexity of the double bundle reconstruction procedure.