Objective  This study aimed to investigate the clinical results of the method of direct lateral structure release in the treatment of severe valgus knee deformity with total knee arthroplasty(TKA).

  Methods  Twenty-eight patients(30 knees) with severe valgus knee deformity underwent TKA with the method of direct lateral soft tissue release with posterior stabilized implants from January 2007 to December 2014. There were 8 males and 20 females, with the ages ranging from 41 to 80 yearsmean(66.7±11.1)years. There were 23 knees of osteoarthritis, 5 knees of rheumatoid arthritis, 2 knees of patella dislocation, and 1 knee of medial instability. Lateral collateral ligament(LCL) and iliotibial band(ITB) were released in all patients, only 2 popliteus(Pops) were released. Clinical and radiographic evaluations including range of motion(ROM), the Hospital for Special Surgery(HSS) knee score, and the tibia and femur angle(T-F angle) were performed at follow-up.

  Results  The duration of follow-up ranged 2 to 8 years. The average HSS score improved from 20.4±14.3 points preoperatively to 89.5±9.4 points at the final follow-up, P < 0.001. The average T-F angle was corrected from 32.6±4.3 to 7.6±3.7, P =0.001. We cured 1 case of lateral instability by using articular branches. 4 patients with palsy of peroneal nerve recovered after 3 months. There had been no complications, such as infection, DVT, or component loosening.

  Conclusions  The techniques of direct lateral soft tissue release(LCL+Pop+ITB) with posterior stabilized implants can correct a sever valgus deformity very successfully in patients undergoing primary total knee arthroplasty, and provide excellent results.