Midterm Follow-up of Opening-Wedge High Tibial Osteotomy

Abstract

Background High tibial osteotomy is a valuable option for patients with varus gonarthrosis. To avoid difficulties with closing-wedge osteotomies, medial opening-wedge high tibial osteotomies have been advocated. Hypothesis Opening-wedge high tibial osteotomy is a good option in highly active patients with varus gonarthrosis who would like to delay or prevent progression to total knee arthroplasty without activity restrictions. Study Design Case series; Level of evidence, 4. Methods Twenty consecutive patients with varus gonarthrosis were treated with a medial opening-wedge high tibial osteotomy using the Puddu plate and allograft bone graft for a prospective study (14 men and 6 women; average age, 49.4 years [range, 36-67 years]). Gait analysis was performed preoperatively and at 6 months postoperatively. Preoperative radiographs, subjective ratings, and knee scores (Lysholm and Hospital for Special Surgery [HSS] scores) were obtained. At 2 years postoperatively and at the latest follow-up visit (average, 8.3 years), the subjective ratings and knee scores were repeated. Results Gait analysis revealed an abnormal weightbearing pattern preoperatively with the vertical ground-reaction force. The postoperative vertical ground-reaction force revealed a normal double peak pattern. The preoperative adduction moment was 29% greater than the 6-month postoperative adduction moment. The preoperative varus averaged 3.6° and was corrected to an average of 7.5° of valgus postoperatively. All patients subjectively rated their preoperative knee as poor. At 2 years postoperatively, most patients (14) rated their knee as good, with 5 excellent and only 1 fair rating. The average preoperative Lysholm and HSS knee scores were 54.2 and 75.9, respectively, compared with the 2-year postoperative averages of 89.1 and 92.7, respectively. At 8 years postoperatively, there was 70% survivorship with 42% of patients rating their knees as good or excellent. Five patients (25%) had undergone total knee arthroplasty. Lysholm and HSS knee scores were 83.0 and 86.8, respectively, for the surviving knees at 8 years postoperatively. Conclusion Medial opening-wedge high tibial osteotomy produces good results in the midterm. After the osteotomy, a more normal appearing weightbearing pattern with double peaks was seen. The adduction moment significantly decreased, resulting in less contact pressure through the medial degenerative compartment of the knee. The authors recommend medial opening-wedge high tibial osteotomy for young patients with varus alignment and medial compartment arthritis to allow this patient population to remain highly active and delay progression to total knee arthroplasty without activity restrictions.