Total knee arthroplasty for severe valgus knee deformity

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 32.72o±9.68 o pre-operation to 4.89o±0.90 o post-operation(P <0.001). The mean range of motion were improved from 93.72o±23.69 o pre-operation to 116.61±16.29 o 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. Postoperative 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.