Anterior opening-wedge high tibial osteotomy for restoring posterior tibial slope in PCL insufficiency and genu recurvatum: A narrative review

Sagittal plane tibial geometry is a critical and modifiable determinant of outcomes in posterior cruciate ligament (PCL) insufficiency and genu recurvatum. The posterior tibial slope normally ranges from 7° to 10°, and pathological mechanics arise when it falls below 5° or becomes reversed. In PCL insufficiency, a flattened slope substantially increases graft failure risk, with long-term data demonstrating markedly reduced 10-year survival for patients with severely flattened medial and lateral slopes. Biomechanically, tibial slope exerts a linear, independently significant effect on PCL graft force in loaded states, and flattened slopes further worsen multiplanar instability following combined ligament reconstruction. In genu recurvatum, a flat or negative slope amplifies a chronic hyperextension moment that overstresses the posterior capsule and posterolateral ligamentous complexes, producing pain, weakness, instability and functional impairment. Both conditions share a common biomechanical root and benefit from surgical correction through anterior opening-wedge high tibial osteotomy (AOW-HTO), which restores physiologic slope by shifting the tibial resting position anteriorly and reducing posterior sag. Surgical planning relies on calibrated radiographs, with each millimetre of opening corresponding to approximately 2° of correction; three-dimensional computed tomography planning with patient-specific cutting guides adds accuracy for complex or biplanar deformities. Three operative approaches are described, supratuberosity, trans-tuberosity and infratuberosity, each with distinct implications for patellar height, healing potential and concurrent ligamentous procedures. Published data report mean slope increases of 9°-24° with 70%-90% good-to-excellent functional outcomes, and modern tuberosity-sparing techniques have expanded indications while preserving patellofemoral mechanics. Principal complications include hinge fractures, patella baja, implant irritation and iatrogenic extension loss, mitigated by meticulous technique and mandatory intraoperative extension testing. Four illustrative cases, spanning recurrent PCL insufficiency, growth-arrest-related recurvatum treated with acute and gradual correction and a biplanar osteotomy combined with revision PCL reconstruction in a professional athlete, demonstrate the breadth of application. The evidence base remains predominantly Level III-IV and prospective comparative studies are needed; nevertheless, AOW-HTO is an effective, joint-preserving procedure and a valuable adjunct to ligamentous reconstruction in patients with pathological sagittal malalignment. LEVEL OF EVIDENCE: Level V.