Background
In patients with chronic multiple ligament-injured knee, failure to correct the varus malalignment of the knee and posterolateral instability will often result in failure of ligament reconstruction. Opening wedge high tibial osteotomy (HTO) can address both the varus and anteroposterior instability.
Purpose
To assess the functional outcomes of opening wedge HTO in treating anteroposterior instability and varus malalignment of the knee in patients with chronic multiple ligament-injured knee.
Patients and methods
Overall, 12 patients with 12 knees with combined grade 3 posterolateral, anterior cruciate ligament (ACL), and posterior cruciate ligament (PCL) instability and varus alignment of the knee were treated with opening wedge HTO. All 12 varus knees had grade 3 posterolateral instability. Moreover, six patients had ACL deficiency, four patients had PCL deficiency, and two patients had combined ACL and PCL deficiency. Posteromedial opening wedge HTO was done for the ACL-deficient knees to decrease the tibial slope. Anteromedial opening wedge HTO was done for the PCL-deficient knees to increase the tibial slope. Knees with combined ACL and PCL deficiency were treated by posteromedial opening wedge HTO to address the ACL deficiency. Second-stage ligament reconstruction was performed in patients with continued instability after the osteotomies had healed and after at least 6 months of rehabilitation.
Results
Of 12 knees, eight had sufficient improvement in knee function that a subsequent ligament reconstruction was not necessary. There was a significant difference between the preoperative and postoperative coronal (femorotibial angle) alignments. There was a significant difference between the preoperative and postoperative posterior tibial slopes in the ACL patient group but not for the PCL patient group. Of six patients with ACL injuries, two required posterolateral complex (PLC) reconstruction, one of them needed in addition ACL reconstruction. Of four patients with PCL injury, one required PLC and PCL reconstruction. Of two patients with combined ACL and PCL injury, one required PLC and PCL reconstruction. Of six patients with high-velocity knee injuries, four needed further ligament reconstruction.
Conclusion
Opening wedge HTO can be an effective method of treatment for patients with combined chronic multiple ligament injuries and varus knee. Patients with an appropriate opening wedge and manipulation of the slope to enhance stability may not require the second soft tissue procedure. Patients with low-velocity knee injuries may not require a second-stage ligament reconstruction after healing the osteotomy and rehabilitation.