PAPER 087: SIMULTANEOUS MEDIAL OPENING WEDGE HTO AND HAMSTRING ACL RECONSTRUCTION: TWO-YEAR CHANGES IN ALIGNMENT, DYNAMIC KNEE JOINT LOAD AND SELF-REPORTED FUNCTION

Abstract

Purpose: Simultaneous high tibial osteotomy (HTO) and anterior cruciate ligament (ACL) reconstruction has been proposed as a treatment for patients with combined medial compartment knee osteoarthritis (OA) and ACL deficiency. Although goals of surgery are to correct malalignment, decrease knee joint load and enable continued participation in sports, few prospective studies evaluating these outcomes exist. Therefore, the objective of this study was to evaluate two-year changes in frontal plane alignment, dynamic knee joint load and self-reported function during sport after simultaneous HTO and ACL reconstruction.

Method: Thirty patients with varus alignment, medial compartment knee OA and ACL deficiency have undergone medial opening wedge HTO and hamstring tendon ACL reconstruction during a single operation. Full-length, standing AP radiographs (mechanical axis angle), dynamic knee joint loads (the peak external adduction moment about the knee during self-paced walking) and the Knee Injury and Osteoarthritis Outcome Scale (KOOS) were completed before and 24 months after surgery.

Results: Based on the 14 patients currently at 24.9 ± 1.67 months postop (12 males; age = 38.5 ± 7.5 yrs.; BMI = 29.5 ± 5.6, median Kellgren and Lawrence grade = 2), mechanical axis angle decreased significantly (p< 0.005) from −6.2 ± 3.63° to 0.29±1.94°. Despite a small (0.06 ± 0.10m/s), but significant (p< 0.05), increase in self-paced walking speed after surgery, the peak knee adduction moment decreased significantly (p < 0.001) from 2.96 ± 0.61 %BW*ht to 1.58 ± 0.48 %BW*ht [mean decrease = 1.38 %BW*ht (95% CI: 0.87 – 1.89)]. Each domain of the KOOS also improved significantly (p< 0.05), with the mean sports and recreation domain increasing (p=0.001) from 26.92 ± 24.29 to 66.54 ± 28.09 [mean increase = 39.62 (95% CI: 20.09 – 51.14)]. Data from 30 patients will be available at time of presentation.

Conclusion: Two-year outcomes after simultaneous medial opening wedge HTO and ACL reconstruction suggest this treatment results in substantial improvements in alignment, knee joint load and self-reported functioning during sport.