title: Total knee arthroplasty for severe valgus knee deformity.
abstract: BACKGROUND
  Primary total knee arthroplasty (TKA) in severe valgus knees may prove challenging, and choice of implant depends on the severity of the valgus deformity and the extent of soft-tissue release. The purpose of this study was to review 8 to 11 years (mean, 10 years) follow-up results of primary TKA for varient-III valgus knee deformity with use of different type implants.
  
  
  METHODS
  Between January 2002 and January 2005, 20 women and 12 men, aged 47 to 63 (mean, 57.19 ± 6.08) years old, with varient-III valgus knees underwent primary TKA. Of the 32 patients, 37 knees had varient-III deformities. Pie crusting was carefully performed with small, multiple inside-out incisions, bone resection balanced the knee in lieu of soft tissue releases that were not used in the series. Cruciate-retaining knees (Gemini MKII, Link Company, Germany) were used in 13 knees, Genesis II (Simth & Nephew Company, USA) in 14 knees, and hinged knee (Endo-Model Company, Germany) in 10 knees. In five patients with bilateral variant-III TKAs, three patients underwent 1-stage bilateral procedures, and two underwent 2-stage procedures. All implants were cemented and the patella was not resurfaced. The Hospital for Special Surgery (HSS) knee score was assessed. Patients were followed up from 8 to 11 years.
  
  
  RESULTS
  The mean HSS knee score were improved from 50.33 ± 11.60 to 90.06 ± 3.07 (P < 0.001). The mean tibiofemoral alignment were improved from valgus 32.72° ± 9.68° pre-operation to 4.89° ± 0.90° post-operation (P < 0.001). The mean range of motion were improved from 93.72° ± 23.69° pre-operation to 116.61 ± 16.29° post-operation (P < 0.001). No patients underwent revision. One patient underwent open reduction and internal fixation using femoral condylar plates for supracondylar femoral fractures secondary to a fall at three years. Three patients developed transient peroneal nerve palsies, which resolved within nine months. Two patients developed symptomatic deep vein thrombosis that was managed with rivaroxaban and thrombo-embolic deterrent stockings. There was no incidence of pulmonary embolism. Post-operative patient satisfaction was 80.7 ± 10.4 points in the groups. Prosthetic survival rate was 100% at mean 10 years postoperative.
  
  
  CONCLUSIONS
  Not only hinged implants can be successfully used in variant-III valgus knees. As our results show, if proper ligament balancing techniques are used and proper ligament balance is attained, the knee may not require the use of a more constrained components. Our results also present alternative implant choices for severe knee deformities.
authors.affiliation: Department of Orthopaedics, Beijing Jishuitan Hospital, Beijing 100035, China.
authors.forename: Xinhua
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Department of Orthopeadic, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China. Email: 52solar@sina.cn.
authors.forename: Min
authors.initials: M
authors.lastname: Wang
authors.affiliation: Department of Orthopeadic, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Liu
authors.affiliation: Department of Orthopaedics, Beijing Jishuitan Hospital, Beijing 100035, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Orthopaedics, Beijing Jishuitan Hospital, Beijing 100035, China.
authors.forename: Yixin
authors.initials: Y
authors.lastname: Zhou
mesh_terms: D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D005260:Female; D006801:Humans; D016916:Joint Deformities, Acquired / Q000601:surgery*; D007719:Knee Joint / Q000601:surgery*; D008297:Male; D008875:Middle Aged