Purpose: We performed clinical and radiographic evaluation of patients with medial compartment osteoarthritis of the knee who had undergone treatment with opening wedge high tibial osteotomy (OWHTO) followed by early full weight bearing. OWHTO procedures were performed by use of TomoFix (Synthes, Bettlach, Switzerland) and bone substitute materials.
Methods: OWHTO was performed in 57 knees in 52 patients with a mean age of 69 years (range, 54 to 82 years) at the time of operation. The diagnosis was primary osteoarthritis in 34 knees in 29 patients and osteonecrosis in a further 23 knees in 23 patients. We established an early weight-bearing exercise program during which these patients were permitted partial weight-bearing exercise 1 week after their osteotomy procedure. All patients performed full weight-bearing exercises at 2 weeks after surgery. The mean follow-up period was 40 months (range, 24 to 62 months).
Results: The American Knee Society Score and Function Score showed significant improvement from 50.9 +/- 12.3 to 91.7 +/- 6.9 points and 59.3 +/- 13.1 to 94.1 +/- 8.8 points, respectively. Before surgery, the mean femorotibial angle during standing was 181.3 degrees +/- 2.4 degrees (1.3 degrees anatomic varus), but it measured 169.6 degrees +/- 2.3 degrees (10.4 degrees valgus) at the time of follow-up. There were no instances of nonunion or implant failure in any of our patients.
Conclusions: We have shown that an early weight-bearing exercise program enables full weight bearing at 2 weeks after OWHTO with TomoFix and artificial bone wedges. Overall, this combination was a highly successful course of treatment for correcting knee malalignment in patients with medial compartment osteoarthritis.
Level of evidence: Level IV, therapeutic case series.