A Hamstring-Based Anatomic Posterolateral Knee Reconstruction With Autografts Improves Both Radiographic Instability and Functional Outcomes

Abstract

Purpose: To report the subjective outcomes and objective stability in a series of chronically grade III posterolateral injured knees treated with a hamstring-based anatomic posterolateral corner (PLC) reconstruction technique using autografts.

Methods: An outcome study of patients with a chronic complete tear of all ligamentous structures of the PLC (>5 mm of varus gapping at 30^o, ≥10° of external tibial rotation during the dial test, ≥4 mm of increased lateral compartment opening during varus stress radiographs) was performed. The patients were evaluated subjectively with Lysholm, International Knee Documentation Committee (IKDC), and Tegner scores and objectively with varus stress radiographs at 20° of knee flexion, IKDC objective scores, and recurvatum evaluation. Institutional review board approval: CEP/UNIFESP n: 1251/2016.

Results: Twenty-nine of 33 patients were available for follow up at an average of 31.9 ± 12.3 months (range, 24-59 months) postoperatively. Twenty-five patients underwent multiple-ligament reconstruction without prior osteotomy. No patient had an isolated PLC knee reconstruction. The average comparative preoperative and postoperative outcomes were, respectively: Lysholm: 49.7 ± 10.3, 81.2 ± 12.8, P < .001, 89.7% met minimal detectable change; IKDC: 36.7 ± 8.3, 70.4 ± 19.8, P < .001, 82.8% met minimal clinically important difference; Tegner, 6.6 ± 1.3, 5.5 ± 1.6, P < .001; and varus stress radiograph: 7.1 ± 3.1 mm, 1.8 ± 1.8 mm, P < .001. A significant improvement, P < .001, was found between preoperative and postoperative IKDC objective scores for varus opening at 0° and 30° and external rotation measured by the dial test at 30°. Recurvatum was also improved: preoperatively, 52% had a low-grade and 48% had a high-grade recurvatum, whereas postoperatively, 100% were classified as low grade, P < .001.

Conclusions: The presented anatomic PLC reconstruction, concomitant to other surgical procedures and ligament reconstructions, is a valid technique in a multiligamentous knee injury involving the PLC, improving subjective outcomes and objective stability in patients with a chronic PLC knee injury, similar to historical controls.

Level of evidence: Level IV, therapeutic case series.