Total knee arthroplasty for severe valgus knee deformity

Abstract

Objective To investigate the surgical methods and clinical effects of total knee arthroplasty (TKA) in patients with severe valgus knee deformity.Methods From January 2007 to December 2012,22 patients with 23 severe valgus knee deformity underwent TKA by means of medial parapatellar approach,standard osteotomy and only lateral soft tissue release with posterior stabilized implants were retrospectively analyzed.They were 7 males and 15 females,aged from 41 to 78 years,with an average age of 65 years.Tibiofemoral angle (angle between the femur and tibia anatomic axis) was 22°-50°,with an average of 34.6±2.4°.Among them,17 cases were osteoarthritis,5 cases were rheumatoid arthritis,3 cases complicated with patella dislocations,1 case complicated with medial instability,3 cases of 4 knees complicated with flexion contracture.Posterior stabilized prosthesis were used in 21 cases of 22 knees,constrained prosthesis were used in 1 case of 1 knee,5 cases accepted intraoperative patellar replacement.Clinical and radiographic evaluations including range of motion (ROM),the Hospital for Special Surgery (HSS)knee score and the tibial and femur angle (T-F angle) were performed at follow-up.Results The duration of follow-up averaged 30.5 months.The average HSS score improved from 19.6±4.7 points preoperatively to 89.7±3.6 points at the time of the last follow up.The average ROM improved from 43.7°-±5.8° preoperatively to 110.6°±7.5°.The average T-F angle was 8.6°±0.8°.We had 5 patella replacements,2 medial instability cured by using articular branches,2 palsies of nervus peroneus communis recovering after 3 months.No complications such as infection,DVT,or component loosening.Conclusion The techniques of medial parapatellar approach,standard osteotomy and only lateral soft tissue release with posterior stabilized implants can deal with a severe valgus knee deformity very successfully in patients undergoing primary total knee arthroplasty,and provide excellent results. Key words: Arthroplasty, replacement, knee; Genu valgum; Osteoarthritis; Arthritis, rheumatoid