Opening focal dome osteotomy in the treatment of varus gonarthrosis associated with medial laxity

Abstract

Objectives: We evaluated the short-term results of opening focal dome osteotomy in the treatment of varus gonarthrosis associated with medial laxity.
Patients and methods: Seventeen knees of 16 patients with varus gonarthrosis associated with medial laxity (15 females, 1 male; mean age 51.6 years; range 45 to 58 years) were managed with opening focal dome osteotomy in our clinic between September 2003 and July 2006. The patients were evaluated for alignment of the lower extremities and medial laxity before and after the operation and were also evaluated clinically by Knee Society (KS) knee scores and Hospital for Special Surgery (HSS) knee scores.
Results: Mean follow-up was 27 months (range 12 to 44 months). Postoperatively, an average 13.8±3.3° mechanical femuro-tibial angle (mFTA) correction was achieved (p=0.001). Average preoperative mechanical varus was 9.9±3.1° whereas the mean postoperative mechanical valgus was 3.9±0.8° (p=0.001). An average 2.6±1.2 mm reduction in medial laxity was ensured. Preoperative joint line convergence angle with a mean of 6.2±1.7° was reduced to 3.2±1.1° postoperatively which was statistically significant (p=0.002). Preoperative KS knee scores and function scores were 49±9 and 44±11 respectively whereas postoperative these values were 89±6 and 84±8 respectively. These values represent an average of 40±12 improvement (p=0.001). Pre- and postoperative HSS scores were 61±8 and 88±7 respectively representing an average of 27±11 improvement (p=0.001).
Conclusion: Medial laxity is observed in a majority of patients with varus gonarthrosis. Opening focal high tibia dome osteotomy can achieve a correction in the mechanical alignment and also decreases medial laxity effectively in knees with varus gonarthrosis.